1. Field of the Invention
The present invention relates to a two-dimensional color code, preparing and restoring method for the code and apparatus therefor in which data is coded by a recording apparatus or a system having a color code reading function, recorded and stored in a recording medium, and original data is restored from the coded data.
2. Description of the Related Art
In the ensuing explanation, a printing apparatus is used as a recording apparatus, and recording on a recording medium will be explained by way of printing on a printing sheet as a specific embodiment.
Bar codes so far well known are that a plurality of bars having a predetermined length is arranged in a row. Data is coded into a predetermined form in the state in which data can be read by an optical reading device, and data is represented by changing the width of bars and the width of a space between bars.
Further, it has been contemplated that the bar codes are colored in order to increase information amount thereof, which is known, for example, from Japanese Published Examined Patent Application No. Sho 61-217887. If there are a plurality of writable and readable colors as bar codes, the information amount recordable with the same density increases accordingly.
On the other hand, a two-dimensional code is contemplated as means for increasing the information amount.
Examples of two-dimensional codes known include one in which plural stages of one-dimensional bar codes are superposed in which a plurality of bars is laterally arranged in one row, and one in which a two-dimensional matrix is formed in a longitudinal direction and a lateral direction, and data is represented by a combination of states of pixels of the matrix.
Coloring of one-dimensional bar codes and coding of many information amounts by use of two-dimensional codes have been realized. However, there is mere use such that goods information in the physical distribution and production is coded to make use of information thereof.
On the other hand, kinds of information that can be coded include not only systematic information applied with codes constituted by English Figures in accordance with the predetermined rule as in goods information, but also plain information not systemized in which analog data is merely digitalized such as image information and voice information.
The latter information amount is much more than the former. If full color image data should be coded, there would require coded printed matter having a large area several times of a printing area of the original data.
Further, when the coded printed matter is made substantially equal to the printing area of the original data, resolution of the restored image results in very poor since information per unit area of the code is less.
Accordingly, in the present method, the data amount capable of being bar-coded is limited not to be able to correspond to coding of full color image data or the like.
Therefore, a system using a disk or the like applied with a magnetic memory as a storage medium is generally used as compared with a system using coded printed matter as a storage medium.
There are merits and demerits according to difference in storage media. The data storage using printed matter has the merit in that no space is occupied and the medium itself is cheap and tends to be lowered in cost. The procedure capable of coding many information with less area has been demanded.
The present invention has been achieved in order to solve the above-described problem. It is an object of the present invention to provide a code, and preparing and restoring method for the code and apparatus therefor, which can code many information amounts with less area and can use printing sheets as storage media even a large capacity of data.